This invention relates to the conversion of aristeromycin into cyclaradine via stereoselective reduction of 3',5'-di-O-protected-2'-keto derivatives of aristeromycin.
Cyclaradine is a known compound which exhibits antiviral activity against the Herpes simplex virus types 1 and 2 and the Vaccina virus.
Vince et al. (U.S. Pat. No. 4,138,562) disclose a multistep, low yield synthesis of cyclaradine from 2-azabicyclo[2.2.1]hept-5-en-3-one.
T. L. Nagabhushan et al. (Abstracts of Papers presented at the 185th ACS National Meeting, Seattle, Wash., Mar. 20-25, 1983, CARB, paper #27) disclose a multistep synthesis of (+)-cyclaradine from (-)-aristeromycin via backside displacement of the 2'-O-triflate group by acetate ion. However, the synthesis is hampered by a low yield of cyclaradine and formation of side-products which are removed by use of expensive purification steps.
There is a need for a process for the conversion of aristeromycin into cyclaradine in high yield and substantially free of chemical and optical impurities without employing expensive purification procedures.